When disruptive behavior problems manifest in very young children, the risk of later antisocial behaviors- including substance abuse, school failure, and criminality-escalates significantly. Evidence-based behavioral parent training (BPT) interventions have demonstrated efficacy and effectiveness in a range of settings in preventing the negative outcomes and costs associated with disruptive behavior problems. However, the public health impact of these interventions has yet to be realized, in part due to reliance on delivery by trained mental health professionals in clinic or community settings. Although implementation studies of BPT have been reported, these results lack generalizability because of their methodological idiosyncrasies in implementation. To maximize the public health benefits of BPT, systematic implementation studies are needed, particularly in underserved community settings. In Appalachia, a region recognized for its dramatic health disparities, at least one in five children exhibits sub-clinical to clinical levels of disruptive behavior problems. Risk factor for child disruptive behavior problems are pervasive; Appalachian residents suffer high poverty rates, low education levels, disproportionately high rates of substance abuse and mental health disorders, and persistent disparities in a wide range of health problems. A challenging combination of cultural barriers and poor access to mental health services hinders the usual delivery model for BPT in Appalachia (i.e., by trained mental health professionals). The vast majority of Appalachian counties are designated as mental health provider shortage areas, and cultural considerations (e.g., distrust of outsiders, the primacy of kinship networks, history of authoritarian parenting styles, strong self-reliance) may limit uptake of the few services available. The goal of this mixed-methods pilot study is to prepare for a future large-scale hybrid effectiveness-implementation trial of an evidence-based BPT intervention across rural Appalachian communities. Our preliminary data revealed community preferences for brief BPT delivery by local community health workers. Thus, to increase the accessibility and acceptability of BPT in this region, we will use the ADAPT-ITT framework to systematically adapt the delivery model for the Family Check-Up, a brief BPT intervention previously shown to be effective in reducing behavior problems and preventing negative outcomes when delivered by trained mental health professionals in clinic and community settings. Following the systematic adaptation of the Family Check-Up delivery model, we will pilot-test its implementation by community health workers in four high-need, under- resourced Appalachian communities to assess feasibility, acceptability, and costs. Our primary questions are whether we can effectively train community health workers in these communities to deliver the Family Check- Up with fidelity; whether we can enroll parents/caregivers and children to initiate and complete the intervention; and whether the battery of assessments and measures planned for the subsequent R01 effectiveness- implementation trial are feasible and appropriate for these community settings.